PHP Custom Autoloader

autoloader.php

<?php

spl_autoload_register(function($classname) {
  $prefix = 'Laundrette\\';
  $length = strlen($prefix);
  if (substr($classname, 0, $length) == $prefix) {
    $filename = 'src/' . substr($classname, $length) . '.php';
    $filename = str_replace('\\', '/', $filename);
    if (file_exists($filename)) {
      require_once($filename);
    }
  }
});